基于稻谷壳模板制备层状硅酸盐催化剂用于CO_(2)加氢反应

利用稻谷壳提供唯一硅源并作为硬模板制备了多孔型层状硅酸盐材料,通过原位还原技术还原层状硅酸盐中的过渡金属离子制得过渡金属基催化剂用于CO_(2)加氢反应。采用扫描电镜(SEM)、X射线粉末衍射仪(XRD)、氮气物理吸附、X射线荧光光谱仪(XRF)、热重分析(TGA)和氢气程序升温还原(H2-TPR)等对稻谷壳模板和所制备的层状硅酸盐催化剂进行了表征。结果表明:利用稻谷壳提供唯一硅源,在水热条件下与单一或混合过渡金属离子成功制得了层状过渡金属硅酸盐材料,制得的层状硅酸盐材料保留了稻谷壳的多层次空间结构。CO_(2)程序升温脱附(CO_(2)-TPD)验证了稻谷壳中的微量碱性金属(K和Ca)能够自掺杂硅酸盐材料,促进其对CO_(2)的吸附。此外,所制备的过渡金属催化剂均能有效催化CO_(2)加氢反应,其中层状硅酸镍的催化活性最高。采用原位红外表征技术探究了层状硅酸镍催化CO_(2)加氢的中间物种信息。结果表明,甲酸盐中间体(HCOO^(*))是生成CO和CH4产物的关键物种。

“滴定法测定二氧化硫”的实验方法改进研究

根据《食品检测与分析实验》教材中的方法,香菇中二氧化硫的测定由于溶液颜色较深影响终点的判断。实验通过水蒸气蒸馏,将馏出液用25 mL 1 mol/L KOH吸收,再通过0.01 mol/L I2标液测定香菇中SO2。同时对实验条件也进行了优化,结果表明:加热时间为110分钟,吸收液浓度为1 mol/L,加入1∶3硫酸10 mL后滴定结果最佳。同时与国标进行对比,偏差为6.7%。改进后的实验操作简单,实验终点易于观察,数据可靠。

Growth and Repair Potential of Three Species of Bacteria in Reclaimed Wastewater after UV Disinfection

Objective The growth and repair potential of three typical microorganisms in reclaimed water after UV disinfection was investigated to assess the effects of photo-reactivation and dark repair of microorganisms,and the microbial safety of reclaimed water following this procedure.Methods The growth and repair potential of Escherichia coli,a fecal coliform strain and Bacillus subtilis in the effluent of a biological wastewater treatment plant disinfected by a low-pressure UV lamp were investigated.Results Any increase in bacterial numbers in the effluent after UV disinfection was due to damage repair.Exposure to photo-reactivating light for 8-10 h after UV irradiation with a dose of 5 mJ/cm 2,the highest percentage of photo-reactivation observed for E.coli and the fecal coliform strain was 29% and 15% respectively.B.subtilis showed little photo-reactivation under these conditions.The percentage of photo-reactivation was related to the UV dose and the photo-reactivating time,and a function was developed to forecast the final concentrations of E.coli and the fecal coliform strain after UV disinfection with possible photo-reactivation.Conclusion Different species of bacteria displayed different responses to UV light and different repair potentials.The repair of indigenous bacteria in wastewater needs to be investigated in future work.

Temperature and symmetry energy of neutron-rich fragments in the 1A GeV^(124,136)Xe+Pb reactions

In this work we study the symmetry-energy coefficient of neutron-rich nuclei,and the temperature dependence of nuclear symmetry energy at low temperatures.An isobaric method is used to extract the symmetry-energy coefficients of neutron-rich nucleus(asym) at zero temperature(T) and asym/T at nonzero temperature in the measured 1A GeV124,136Xe+Pb reactions.T of fragment is obtained from the ratio of its asym to asym/T.The results show that,for fragment with the same neutron-excess(I=N Z),the heavier the fragment is,the higher T it has,and T tends to saturate around 1 MeV for the large mass fragments.It is also shown that the more neutron-rich the isobar is,the higher temperature it has.The T2dependence of symmetry energy of finite nucleus at low temperatures is verified by the extracted results.

以博物馆为中心的文化遗产机构信息融合策略

文化遗产机构的信息融合,是推动我国建设高质量的文化服务供给体系和文化大数据体系的重要路径之一。然而,当前我国文化遗产机构信息融合的范围窄、深度浅、模式陈旧,尚未发挥出聚合效应。博物馆作为文化遗产机构的重要组成部分,因其具有馆藏资源丰富、观众研究成果扎实、阐释链条完整等优势,具备主导文化遗产机构信息融合的条件。本文基于活动理论框架,提出了以博物馆为中心,以模式层、数据层、应用层为中介要素的活动系统,归纳了信息共享、交流、协作、生产四位一体的文化遗产机构信息融合模型,推动搭建以文化遗产机构馆藏资源为基础的展示平台,指导未来文化遗产机构信息融合的实践探索。